Filterable dispersion of glycoxides in lubricating oils



. 2,945,812 FETERAB'LEDISPER-SION F GLYcoxmEs IN nuB rcATrNG ons FrankA. Stuart,"329;La Espiral, '0rinda, Calif., and R. Brashear, 30- Alwin Road, Walnut Creek,

N o Drawing. Filed ,Sept. 30, 1 958, Ser. No. 764,226

" momma. (o1. zs2--s3.-s

tion of internal combustion engines include the sulfuric :acid resulting from the oxidation of sulfur in the fuel, the hydrochloric and hydrobromic acids from the lead scavengers, and the carboxylic acids formed by the incomplete combustion of the fuel and the liquid phase oxidation of the lubricating oil. All of these acids cause engine wear due to chemical attack on the metal. thermore, the sulfuric acid reacts. vigorously with the lubricating oil at elevated temperatures to produce resinous products which contribute 'to' engine fouling; :and portions of the carboxylic acids polymerize to form. resinous deposits or sludge. Numerous lubricating oil :additives have been developed to neutralize these acid ibodies which are formed in lubricating oils.

Lindstrom .et al. ;U.S. Patent 2,676,925 and patent apflication Serial No. 412,666 ;(filed February 25, 1954, .now abandoned), :teach that certain basic substances are markedly effective in inhibiting the formation of these acids in lubricating oils. As taught, these basic sub stances are alkaline .earth metal basic substances which :are obtained .as colloidal dispersionsI(colloidal;solutions) in lubricating oil compositions by dissolving (orrdispersing) alkaline earth metal oxides (or hydroxides) s(e.g., Ca(Ol-I) in a dihydric alcohol (e.g., ethylene :glycol), and blending the resulting dihydric alcohol solu- :t-ion .(or dispersion) with a lubricating oil containingga idispersant (e.g., a polyvalent metal suifonate); After rthe water and unreacted dihydric alcohol are removed, rthe mixture is filtered to remove any undissolved (or unrdispersed) metal basic substance. i

The filtration step in the above process was found to he slow and cumbersome, requiring considerable time iforfiltratio-n. Woodrufi et al. US. PatentNo. 2,716,087

large enough particular size, they could be removed by filtration. However, removal thereof from the lubricating oil composition also removed acid-neutralizing basic materials from the lubricating oil, which oil then became jmcre readily susceptible to theattack by the acidic prodatenr Fura.

V Patented July-19, 1960 No. 2,716,087, without the deleterious wear effects caused by the calcium glycolate trihydrate crystals.

According to this invention, it has been discovered that lubricating oil compositions containing large amounts of basic substances are obtained by forming an admix" ture of a lubricating oil, a dihydric alcohol, a metal oxide (or hydroxide), a dispersant, an alpha-hydroxy acid, and a low molecular weight, non-hydroxy monobasic carboxylic acid; then filtering said admixture, and removing dihydric alcohol;

Lubricating oil compositions prepared by this process will neutralize greater amounts of acidic substances than possible by former lubricating oil compositions.

In the formation of lubricating oil compositions herein, alkaline earth metal oxides and hydroxides are used as initial reactants. Thus, the lubricating oil compositions are prepared by dissolving an alkaline earth metal base. (i.e., an alkaline earth metal oxide or hydroxide) in a dihydric alcohol (e.g., ethylene glycol). An' adrnix-tu-re-is then formed with this dihydric alcohol solution, an alpha-hydroxy acid, a low molecular weight non-hydroxy monobasic carboxylicacid, a lubricating oil, and an oil-solubledispersant. This admixture is ,heated to remove excess, unreacted dihydric alcohol, then filtered, forming a clear, filterable lubricatingoil' composition.

Although. the metal oxides orhydroxides are initial reactants, the dihydric alcohol (i.e., an alkylene glycol) combines therewith to form an alkaline earth metal material which is an alkaline earthmetal basic salt. Thus, as used herein, the alkaline earth, metal material, i.e., the basic salt, meansthe product resulting from the reaction of the alkaline earth metal base and the dihydric alcohol. This alkaline earth metal material also caube described as a glycoxide or a glycolated metal base. (The noted reaction, is described in Organic Reagents in Inorganic Analysis, page 304, by Ibert Mellan published by Blackiston Publishing Company (1941).) p

. Metaloxides and, hydroxides usedhereinasreactants 'vvith thedihydric alcohols to form the metal glycoxides (i.e., ,the'metal basic-salt) "include the alkaline earth "metal oxides andjhydroxides (i.e.,'the'oxides and hy- 5 carbon atoms; in particular, these. glycols include vicinal-alkane diols having less than 5 carbon atoms. Suitable dihydric alcohols include, forexample, ethylene glycol, propanejdiol li; butane diol-2,3 butane diol-1,2;

etc. Ethylene glycol is preferred,because, by the use thereof, greater amounts of metal base can be incorpoas noted her einabove, upon the. metal oxides or hydroxides, which areused in the preparationlof dispersionsof metal base salts. In general, the useof a low molecular weight dihydric alcohol (e.g., ethylene glycol) results; in obtaining-a "greater amount of tlie materials dispersed in the lubricating oil than the use of a higher molecular weight dihydric alcohol '(e.g., propylene glycol) when both are used in the same amounts by weight. It is preferred to select a dihydric alcohol in which the dispersants and the metal oxides or hydroxides have the greatest solubility.

In the formation ofsolutions of metal basic materials in glycols, it .is beneficial-to use certain ratiosby weight 3 of the dihydric alcohol to the metal oxide or hydroxide. These ratios may vary from about 50:1 to about 2:1, 30:1 to about :1 being preferred.

The primary filtering agents of Woodrufi, US. Patent No. 2,716,087, are alpha-hydroxy acids containing no more than 3 carbon atoms, (e.g., glyeolic acid and lactic acid), including the alkaline earth metal salts thereof (particularly the calcium salts) and mixtures thereof.

The low molecular weight non-hydroxy monobasic carboxylic acids herein are those containing no more than 2 carbon atoms (e.g., formic acid and acetic acid, including the alkaline earth metal salts, particularly the calcium salts thereof), and mixtures thereof.

For purposes of this invention, the nonhydroxy monobasic carboxylic acids are present in combination with the alpha-hydroxy carboxylic acids in such proportions that the non-hydroxy monocarboxylic acids constitute from 35 mole percent to about 80 mole percent of the combination. Optimum results are obtained when the non-hydroxy monobasic carboxylic acids are present in the combination in amounts such as to constitute about 50 mole percent to about 65 mole percent of the combination; that is, the non-hydroxy carboxylic acid-alpha-hydroxy carboxylic acid mole ratio is from about 35:65 to about 80:20 (50:50 to about 65:35 being preferred).

The amount of the combination of low molecular weight non-hydroxy monobasic carboxylic acids plus alpha-hydroxy acids (or the calcium salts thereof) used is dependent upon the amount of alkaline earth metal glyeoxides present in the lubricating oil compositions. The mole ratio of this combination (that is, the mole ratio of the combination of non-hydroxy monobasic earboxylic acids plus alpha-hydroxy carboxylic acids), when considered as free acid, to the alkaline earth metal glycoxide can vary from about 0.2 to about 0.5, with the preferred mole ratio varying between about 0.3 and 0.4.

The dispersants used according to the invention to stabilize dispersion of metal basic salts include alkaline earth metal sulfonates, sulfates, phosphonates, thiophosphonates, phosphates, thiophosphates, phenates, naph- -thenates, carboxylates, etc.

The preferred dispersants are sulfonates, in particular the alkaline earth metal sulfonates wherein the organic radicals are derived from dodecane, hexadecane, eicosane, triacontane,- mineral oil fractions, etc., which may be exemplified by calcium white oil benzene sulfonate, magnesium white oil benzene sulfonate, calcium dipolypropene benzene sulfonate, magnesium dipolypropene ben- Zene sulfonate, calcium mahogany, petroleum sulfonate, magnesium mahogany petroleum sulfonate, calcium triacontyl sulfonate, magnesium triacontyl sulfonate, calcium lauryl sulfonate, magnesium lauryl sulfonate, etc. The particularly preferred metal "for these sulfonates is calcium.

v The dispersants can be used in amounts of about 0.1% to 10%, by weight, of said finished composition. However, it is preferred to use from about 0.3% to about 2.0%, by weight, because lubricating oil compositions containing these amounts markedly improve the overall ratings of an engine.

, Expressed in millimoles per kilogram of final lubricating oil composition, the dispersants can be used in amounts ,of -about l millimole per kilogram to about 110 millimoles per kilogram, with a preferred range of about. 3 millimoles per kilogram to about 20 millimoles per kilogram.

The, amount of metal basic materials (e.g., alkaline earth metal basic materials) which are dispersible in the .lubricating oil compositions herein is dependent on the amount of dispersant which is present. Normally, one part by weight of a dispersant can stably disperse as much as 0.2 part or more by weight of the alkaline earth metal basic materials. For example, one part byxwjeight of an alkaline earth metal petroleum mahogany sulfonate can stably disperse 0.2 part by weight of an alkaline earth metal basic material. Expressed otherwise, 1 mole of an alkaline earth metal petroleum mahogany sulfonate can stably disperse at least 1.75 moles of an alkaline earth metal basic material. Thus, the alkaline earth metal basic materials and dispersant are present in the lubricating oil compositions in such amounts that the basic material/ dispersant mole ratios have values of at least 1.75, and as high as 4.0; preferably, from about 2.0 to about 3.0.

In terms of the alkaline earth metal oxides and bydroxides which are initially incorporated into the lubricating oil compositions, the amounts of these oxides and hydroxides can vary from 0.2% to about 7.0%, by weight.

In addition to the above considerations, the type of base oils which are used influence the amount of alkaline earth metal basic materials which are dispersed in the oil. For example, alkaline earth metal sulfonates are more soluble in lubricating oils of high aromatic or naphthenic content than in lubricating oils having only minor aromatic or naphthenic content.

Suitable lubricating oils useful as the base oils of the composition of this invention include a wide variety of lubricating oils, such as oils which can be manufactured by solvent treating, acid treating, etc.; various crude oils, such as parafinic, naphthenic, or mixed base crude oils, or such as those which can be obtained by synthesis, ,e.g., the Fischer-Tropsch process. Lubricating oils also include those derived from coal products and synthetic oils, e.g., alkylene polymers, such as polymers of propylene, butylene, etc., and mixtures thereof; alkylene oxide type polymers; dicarboxylic acid esters and liquid esters of acids of phosphorus. Synthetic oils of the alkylene oxide type polymers which may be used include those exemplified by alkylene oxide polymers (e.g., ropylene oxide polymers) and derivatives, including alk' 'lene oxide type polymers prepared by polymerizing alkylene oxides (e.g., propylene oxide) in the presence of Water or alcohols, e.g., ethyl alcohol; and esters of alkylene oxide type polymers, e.g., acetylated propylene oxide type polymers prepared by acetylating the propylene oxide polymers containing hydroxyl groups.

Alkaline earth metal basic materials are dispersed in lubricating oil compositions in accordance with this invention by heating a mixture of a dispersant (e.g., an alkaline earth metal sulfonate), an alkaline earth metal oxide and/or hydroxide, a dihydric alcohol, an alpha-hydroxy monocarboxylie acid, and a low molecular Weight non-hydroxy monoearboxylic acid in the lubricating oil to a temperature ranging from about F. to about 400 F. (250 F. to 350 F. being preferred) for a period of time sufficient to promote the reaction between the alkaline earth metal oxide (or hydroxide) and the dihydric alcohol. During this heating process, the alkaline earth metal basic substance is dispersed in the lubricating oil composition, and substantially all 'of the remaining apparently unreacted dihydric alcohol aid (Celite), one-half inch thick, was placed on the filter paper, and vacuum was applied'to the flask so that the absolute pressure was 18 inches of mercury. The oil preparation was poured onto the filter at a, temperature of 375 F., and time for filtration recorded. 7

The following test was made to ascertain theeffectiveness of the no'n-hydroxy acids (or the alkaline earth salts thereof) in inhibiting crystal formation as described herein: A

50 grams of the compounded lubricating oil was placed in a 250 ml. beaker, and 2% water was added. The mixture was agitated, and allowed tog-stand. Observations were made over a 24 hour period for the appearance of needle-like crystals.

EXAMPLE .1.A CALCIUM GLYCOXIDE LUBRI- CATING on. COMPOSITION CONTAINING A MIXTURE OF GLYCOLIC ACID AND ACETIC ACID-- 7 20.5 grams of calcium hydroxide were dispersed in 243 grams ofethylene glycol. To this mixture was added 200 grams of a lubricating oil solution of a calcium mahogany sulfonate (the lubricating oil solution containing 1.64% calcium) and 53 grams of a California solvent-refined base oil having a viscosity of 350 SSU at 100 F. To this mixture was further added 16:1 grams of 70% glycolic acid and 4.3 grams of glacial acetic acid. The ethylene glycol was then removed by distillation to a:temperature* of 375 f F. at an absolute pressure of 50-m-m.'of mercury. The composition wasthen filtered to remove any undispersed calcium hydroxide. The filter rate was 14.0 grams per minute.

p The filtered lubricating oil contained 2.72 moles of baseper. mole ofcalcium sulfonate, the base consisting of 56.4% calcium from calcium glycoxide and 43.6%

calcium from calcium acetate and calcium glycolate.-

Nocrystals'were observed as determined by the crystal formation test. I

To a mixture of 19.1 grams of calcium hydroxide and 227 grams of ethylene glycol was added 224 grams of a mineral oil solution of calcium mahogany sulfonate having a sulfonate calcium content of 1.46%, 45.6 grams of a California solvent-refined petroleum oil hav- 7 ing a viscosity of 350 SSU at 100 F., 9.6 grams of 70% glycolic acid and 2.7 grams of chemically pure ethylene glycol was removed by heating the mixture to formic acid. The ethylene glycol was distilled off to a temperature of 375 F. at an absolute pressure of mm. of mercury, and the composition was filtered. The filter rate was 33 grams per minute. The filtered lubricating oil contained 2.64 moles of base per mole of calcium sulfonate, the base consisting of 70% calcium from calcium glycoxide and 30% calcium from calcium formate and calcium glycolate. No crystals were observed as determined by the crystal formation test.

EXAMPLE 3.-FILTRATION AGENT CONSISTING OF A MIXTURE OF GLYCOLIC ACID AND FOR- MIC ACID M To a mixture of 83-lbs. of calcium'hydroxi de in 975 lbs. of'ethylene glycol-was added 923. lbs. of a mineral oil solution of calcium mahogany petroleum sulfonate (the oil solution having a sulfonate calcium content of 1.45%), 172 lbs. of California solvent-refined petroleum oil havingpa viscosity of 350 SSU at 100 F., 27.5 lbs. of 70% glycolic acid and 19.5 lbs. of 90% formic acid. The ethylene glycol was removed by heating the mixture to 375 F. at an absolute'pressure of mm. of mercury. The mixture was then blown with nitrogen for one hour at atmospheric pressure and 375 F. The resultingcomposition filtered readily on a3 sq. ft. Oliver filter at a rate of 7.5 gallons persq. ft. perhour.

The filtered lubricating oil composition contained 32 moles of base per mole of calcium sulfonate; the base 'formate plus calcium glycolate.

consisting of 68.9% calcium'from calcium glycoxide and 31.1% calcium from calcium formate and calcium glycolate. No crystals were observed.

EXAMPLE 4.-A CALCIUM GLYCOXIDE CON- 19.1 grams of calcium hydroxide were dispersed in 227 grams of ethylene glycol. To this mixture was added a mineral oil dispersion of calcium mahogany sulfonate (the oil having a sulfonate calcium content of 1.46%) and 69.6 grams of ,a California solvent-refined mineral oil having a viscosity of 350 SSU at 400 F., 5.33 grams of glycolic acid, 2.35 grams of chemically pure formic acid, and 2.94 grams of glacial acetic acid. The

375.F. at an absolute pressure of 50 mm. of-mercury and the composition was filtered. The filtration rate in this example was 13 grams per minute.

The filtered lubricating oil composition contained 3.17 moles of base per mole of calcium sulfonategjhe base consisting of 70% calcium from calciumglycoxide plus 30% calcium from calcium formate, calcium acetate and calcium glycolate. No crystal formation was observed.

EXAMPLE 5. A CALCIUM GLYCOXIDE CON- TAINING LUBRICATING OIL COMPOSITION HAVING INCORPORATEDTHEREIN GLYCOLIC ACID f To a mixture of 56 lbs. of calcium hydroxide and 1,380 lbs. of ethylene glycol was added 520 lbs. of a mineral oil solution of calcium mahogany sulfonate (the oil solution having a calcium content of 1.67%), 173 lbs..of a California solvent-refined petroleum oil having a viscosity of 350 SSU at F., and 71 lbs. of a 70% solution of glycolic acid. The ethylene glycol wasremoved by heating the whole mixture to 375 F. at an absolute pressure of 60 mm. oflmercury. Nitrogen was bubbled through the mixture at this temperature and pressure to be sure of removing last traces of ethylene glycol.

. Three such batches as the above were prepared and combined for filtration on a 20 sq. ft. Oliver filter. The filtration rate was 7.5 gallons per square foot per hour. The filtered product contained.3.47 moles of base per mole of calcium sulfonate, the base consisting of 52.6% calcium from calcium glycoxide and 47.4% calcium from calcium glycolate crystals formed.

, The amounts of additivesin the lubricating oil compositions of Example 6 hereinbelow are given in terms of millimoles of metal per kilogram of finished lubricating oil composition. That is, when a certain amounttof a calcium alkyl phenate is given as 4.7 mM;/kg., it means that the finished composition contains 4.7 millimoles of calcium (from the calcium alkyl phenate) per kilogram calcium sulfonate. The base consisted of 65% calcium from calcium glycoxide, and 35% calcium fromv calcium The following Table I further shows the lack of crystal formation in the highly basic lubricating oil compositions of'this invention.

Table l- Appearance of Oil After Storage Clear-No Crystals Clear-No Crystals Clear.No Crystals Clear-No Crystals. Cloudy-Extensive Final Lube Oil Composition of Example 6.- Clear-No Crystals.

Thus, whereas upon storage lubricating oil cprnposb tions of Woodrufi US. Patent No. 2,716,087 gradually lose large proportions ofthe basic component, so thatthe final composition is'corrosive to metals susceptible to acid corrosion, the lubricating'oil compositions of this inven-: tion are stableon storage, retaining all of the essential components necessary to inhibit corrosion.

The following tests were made, for the purpose of ascertaining the formation of glycoxides in the lubricating oil compositions prepared by the process of this invention. If a glycoxide is formed when an alkaline. earth metal oxide is reacted with an aikylene glycol (e.g., ethylene glycol), the following reaction should take place:

a: wagon:

mc om+Mo-+H,c om+m n. n o-M o wherein M is a metal.

EXAMPLE 7 EXAMPLE 8 A mixture of 65.0 grams of barium oxide, 330 grams of ethylene glycol, and 200 grams of benzene was agitated in a reaction flask. The mixture was heated at the reflux temperature .of benzene, during which .time the water was removed by azeotropic distillation. 9.5 cc. of a water ethylene glycol mixture was collected in the water distillation trap. The refractive. index of this water-glycol mixture was 1.3486 which showed that the mixture contained 84% water and 16% ethylene glycol. Therefore, the amount of water resulting from the reaction of the barium oxidewith the ethylene glycol was 7.95 gram (theoretical=7.65 grams). 7 I

We claim: V

1. Inthe process of preparing lubricating oil compositions containing an alkaline earth metal glycoxide by forming an admixture of a lubricating oil, a dihydric alcohol containing less than. carbon atoms, from 0.2% to 7%, by weight, of an inorganic substance selected from the group consisting of alkaline earth metal oxides and hydroxides, an alpha-hydroxy carboxylic acid containing no more than 3 carbon atoms, and from 0.1% to by Weight, of an oil soluble alkaline earth metal sulfonate, heating .to remove dihydric alcohol, and filtering said admixture, the improvement comprising. the process of blending into said admixture prior to filtration, a nonhydroxy monobasic carboxylic'acid selected from the group consisting of formic acid'and acetic acid, wherein said non-hydroxy carboxylic acid-and saidalpha-hydroxy carboxylic acid are present in a mol ratio of 35:65 to a 80:20, wherein the mol ratio of the combinationof alphahydroxy carboxylic'acid and non-hydroxy carboxylicacid to said glycoxide has a value from 0.2 to 0.5, wherein the mol ratio of said inorganic substance to said sulfonate has a valuefrom 1.75 to 4.0, andwherein the mol ratio of said dihydric alcohol to said inorganic substance is from 50:1 to 2:1. 1

2. In the process of preparing lubricating oil compositions containing an alkaline earth metalglycoxide by forming an admixture of a lubricating oil, a dihydric alcohol containing .less than 5 carbon atoms, from 0.2% to 7%, by weight, of an inorganic substanceselected .frorri ithle group consisting of alkaline earth metal oxides and bydroxides, an alpha-hydroxy carboxylic acid containing no more than 3 carbon-atoms, and from 0.3% to 2.0%, by

weight, of an oilsoluble alkaline earth metal sulfonate,,

heating-to remove dihydric alcohol, and filtering said admixture, the improvement comprising the process of blend:

ing into said admixture prior to filtration, a non-hydroxy monobasic carboxylic acid selected from the group consisting of formic acid and acetic acid, wherein said nonliydroxy carboxylic acid and said alpha-hydroxy carboxylic acid are present in a mol ratio of 35:65 to :20, wherein the mol ratio of the combination of alpha-hydroxy carboxylic acid and non-hydroxy carboxylic acid to said glycpxide has a value from 0.2 to 0.5, wherein the mol ratio of said inorganic substance to said sulfonate has a value from 1.75 to 4.0, and wherein the mol'ratio of said dihydric alcohol to said inorganic substance is from 50:1 to 2: 1.

3. In the process of preparing lubricating oil compositions containing an alkaline earth metal glycoxide by forming an admixture of a lubricating oil, a dihydric alcohol containing less than 5 carbon atoms, from 0.2% to 7%, by weight, of an inorganic substance selected from the group consisting of alkaline earth metal oxides and hydroxides, an alpha-hydroxy carboxylic acid containing no more than 3 carbon atoms, and from 0.3% to 2.0%, by weight, of an oil soluble alkaline earth metal sulfonate, heating to remove dihydric alcohol, and filtering said admixture, the improvement comprising the process of blending into said admixture prior to filtration, a non-hydroxy monobasic carboxylic acid selected from the group consisting of formic acid and acetic acid,'wherein said non hydroxy carboxylic acid and said alpha-hydroxy carboxylic acid are present in a mol ratio of 35:65 to 80:20, wherein the mol ratio of the combination of alpha-hydroxy carboxylic acid and non-hydroxy carboxylic acid to said glycoxide has a value from 0.2 to 0.5, wherein the mol ratio of said inorganic substance to said sulfonate has a value from 2.0 to 3.0, and wherein the mol ratio of said dihydric alcohol to said inorganic substance is from 50:1 to 2:1.

4. In the process of preparing lubricating oil compositions containing an alkaline earth metal glycoxide by forming an admixture of a lubricating oil, a dihydric alcohol containing less than 5 carbon .atoms, from 0.2% to 7%, by weight, of an inorganic substance selected from the group consisting of alkaline earth metal oxides and hydroxides, an alpha-hydroxy carboxylic acid containing no more than .3 carbon atoms, and from 0.3% to 2.0%, by weight, of an oil soluble alkaline earth metal sulfonate, heating to remove dihydric alcohol, and filtering said admixture, the improvement comprising the process of blending into said admixture prior to filtration, a non-hydroxy monobasic carboxylic acid selected from the group consisting'of formicacid and acetic acid, wherein said non-hydroxy carboxylic acid and said alpha-hydroxy carboxylicacid are present in a mol ratio of 50:50 to 65:35, wherein the mol ratio of the combination of the alpha-hydroxy carboxylic acid and non-hydroxy carboxylic acid to said glycoxide has a value from 0.2 to 0.5 wherein the mol ratio of said inorganic substance to said sulfonate has a value from 2.0 to 3.0, and wherein the mol ratio of said dihydric alcohol to said inorganic substance is from 50:1 to 2:1.

5. In the process of preparing lubricating oil compositions containing an alkaline earth metal glycoxide by forming an admixture of a lubricating oil, ethylene glycol, from 0.2% to 7%, by weight, of an inorganic substance selected from the group consisting of calcium oxide and calcium hydroxide, an alpha-hydroxy carboxylic acid containing no more than 3 carbon atoms, and from 0. 1% to 10%, by weight, of an oil soluble calcium sulfonate, heating to removedihydric alcohol, and filtering said admixr t e iainrq e emsq r ns t e rq essp b n #929 id emf... are Pri r t lt a ion ac ea si. re.-

in said acetic acid and said alpha-hydroxy carboxylic acid are present in a mol ratio of 35:65 to 80:20, wherein the mol ratio of the combination of alpha-hydroxy carboxylic acid and acetic acid to said glycoxide has a value from 0.2 to 0.5, wherein the mol ratio of said inorganic substance to said sulfonate has a value from 2 to 3, and wherein the mol ratio of said ethylene glycol to said inorganic substance is from 50:1 to 2: 1.

6. In the process of preparing lubricating oil compositions containing alkaline earth metal glycoxides by forming an admixture of a lubricating oil, ethylene glycol, from 0.2% to 7%, by weight, of an inorganic substance selected from the group consisting of calcium oxide and calcium hydroxide, an alpha-hydroxy carboxylic acid containing no more than 3 carbon atoms, and from 0.1% to 10%, by weight, of an oil soluble calcium petroleum sulfonate, heating to remove dihydric alcohol, and filtering said admixture, the improvement comprising-the process of blending into said admixture prior to filtration,-

acetic acid, wherein said acetic acid and said alpha-hydroxy carboxylic acid are present in a mol ratio of 35 :65 to 80:20, wherein the mol ratio of the combination of alpha-hydroxy carboxylicacid and acetic acid to said glycoxide has a value from 0.2 to 0.5, wherein the mol ratio of said inorganic substance to said sulfonate has a value from 2 to 3, and wherein the mol ratio of said ethylene glycol to said inorganic substance is from :1 to 10:1.

7. A lubricating oil composition comprising a lubricating oil, an alkaline earth metal glycoxide containing no more than 5 carbon atoms in an amount of 0.02% to 7.0%, by weight, based on the oxide of said alkaline earth metal, an alkaline earth metal salt of an alphahydroxy carboxylic acid containing no more than 3 carbon atoms, an alkaline earth metal salt of a non-hydroxy carboxylic acid selected from the group consisting of acetic acid and formic acid, from 0.1% to 10%, by weight, of an alkaline earth metal sulfonate, wherein said salt of non-hydroxy carboxylic acid is present in an amount from about 50 mol percent to 65 mol percent of the total amount of the combination of said salt of i boxylic acid salt to said glycoxide has a value from 0.2

to 0.5, and wherein the mol ratio of said oxide of alkaline earth metal to said sulfonate has a value from 0.75 to 4.0.

8. A lubricating oil composition comprising a lubricating oil, an alkaline earth metal glycoxide containing no more than 5 carbon atoms in an amount of 0.02% to 7.0%, by weight, based on the oxide of said alkaline earth metal, an alkaline earth metal salt of an alpha-hydroxy carboxylic acid containing no more than 3 carbon atoms, an alkaline earth metal salt of acetic acid, from 0.3% to 2.0% by weight, of an alkaline earth metal petroleum sulfonate, wherein said acetate is present in an amount from about mol percent to about mol percent of the total amount of the total combination of said salt of alphahydroxy carboxylic acid and said salt of acetic acid, wherein the mol ratio of the combination of said alphahydroxy carboxylic acid salt and said salt of acetic acid to said glycoxide has a value from 0.2 to 0.5, and wherein the mol ratio of said oxide of alkaline earth metal to said sulfonate has a value from 2 to 3.

9. A lubricating oil composition comprising a lubricating oil, a calcium glycoxide containing no more than 5 carbon atoms in an amount of 0.02% to 7.0%, by weight, based on the oxide of said calcium, a calcium salt of an alpha-hydroxy carboxylic acid containing no more than 3 carbon atoms, a calcium salt of acetic acid, from 0.3% to 2.0%, by weight, ofa calcium petroleum sulfonate, wherein said acetate is present in an amount from about 50 mol percent to about 65 mol percent of the total amount of the total combination of said salt of alpha-hydroxy carboxylic acid and said salt of acetic acid, wherein the mol ratio of the combination of said alpha-hydroxy carboxylic acid salt and said salt of acetic acid to said glycoxide has a value from 0.2 to 0.5, and wherein the mol ratio of said oxide of calcium to said sulfonate has a value from 2 to 3.

10. The lubricating oil composition of claim 9 wherein said alpha-hydroxy carboxylic acid is glycolic acid.

References Cited in the file of this patent UNITED STATES PATENTS 2,079,051 Sullivan et al. Mar. 4, 1937 2,676,925 Lindstrom et al. Apr. 27, 1954 2,716,087 Woodrufi et al. Aug. 23, 1955 UNITED STATES PATENT "OFFICE CERTIFICATE OF CORRECTION Patent'No, 2,945,812 July 19 1966 Frank A. Stuart et alo It is herebfi certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below..

Column 4, line 13, for "02%" read 0o2% Signed and sealed this 4th day of April 1961,

(SEAL) Attest; W.

XWXXXZXNX ARTHUR w. CROCKER Attesting Oflicer A ting Commissioner of Patents 

1. IN THE PROCESS OF PREPARING LUBRICATING OIL COMPOSITIONS CONTAINING AN ALKALINE EARTH METAL GLYCOXIDE BY FORMING AN ADMIXTURE OF A LUBRICATING OIL, A DIHYDRIC ALCOHOL CONTAINING LESS THAN 5 CARBON ATOMS, FROM 0.2% TO 7%, WEIGHT, OF AN INORGANIC SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF ALKALINE EARTH METAL OXIDES AND HYDROXIDES, AN ALPHA-HYDROXY CARBOXYLIC ACID CONTAINING NO MORE THAN 3 CARBON ATOMS, AND FROM 0.1% TO 10%, BY WEIGHT, OF AN OIL SOLUBLE ALKALINE EARTH METAL SULFONATE, HEATING TO REMOVE DIHYDRIC ALCOHOL, AND FILTERING SAID ADMIXTURE, THE IMPROVEMENT COMPRISING THE PROCESS OF BLENDING INTO SAID ADMIXTURE PRIOR TO FILTRATION, A NONHYDROXY MONOBASIC CARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF FORMIC ACID AND ACETIC ACID, WHEREIN SAID NON-HYDROXY CARBOXYLIC ACID AND SAID ALPHA-HYDROXY CARBOXYLIC ACID ARE PRESENT IN A MOL RATIO OF 35:65 TO 80:20, WHEREIN THE MOL RATIO OF THE COMBINATION OF ALPHAHYDROXY CARBOXYLIC ACID AND NON-HYDROXY CARBOXYLIC ACID TO SAID GLYCOXIDE HAS A VALUE FROM 0.2 TO 0.5, WHEREIN THE MOL RATIO OF SAID INORGANIC SUBSTANCES TO SAID SULFONATE HAS A VALUE FROM 1.75 TO 4.0, AND WHEREIN THE MOL RATIO OF SAID DIHYDRIC ALCOHOL TO SAID INORGANIC SUBSTANCE IS FROM 50:1 TO 2:1. 